Sydney faces a major bushfire outbreak as emergency crews battle more than 30 blazes around Australia's biggest city. The New South Wales government says the fires are some of the worst Australia has ever seen.

A dark cloud of smoke hangs over central Sydney as forest fires continue to burn out of control in an arc around the city.

Three-thousand firefighters have been mobilized. More than 80 aircraft are part of the effort, including giant helicopters capable of dropping 9,000 liters of water at one go.

John Winter from the New South Wales Fire Service says the scale of the emergency was unexpected.

"The sheer sudden number of new fires that occurred across the Sydney area has really taken everyone by surprise and is clearly stretching our resources," he said. "Crews are doing their best to get to each of these new fires and to combat them as they can."

The fires have brought chaos to this city of four million people. Many highways have been closed and underground train stations evacuated due to power surges.

The Premier of New South Wales, Bob Carr, has announced immediate finacial aid for the victims of the fires. Mr. Carr says the situation is far worse than last year's Christmas-week fires, which devastated much of the region.

The authorities think many of the outbreaks were started deliberately by arsonists or by acts of negligence, such as carelessly dropped cigarettes.

The military has been ordered to join the firefighting operation. At one army camp southwest of Sydney, soldiers were fighting a serious fire. A spokesman said some troops are beating down the flames with their jackets.

The weather will continue to be the enemy in the next 24 hours. Strong winds are fanning the flames, temperatures are expected to soar in the coming days and there is little chance of rain.

The region around Sydney is considered to be one of the most bushfire-prone regions in the world. A long drought has made the dangers even more acute.